Self-assembling polymers could boost computer memory

SAN FRANCISCO—Researchers at the University of Texas-Austin have developed a technique using directed self-assembly (DSA) of block copolymers that they say could boost the storage capacity of hard disk drives by a factor of five.

Current production methods for writing zeros and ones as magnetic dots on a metal surface are nearing the point of maxing out, as packing more dots into tighter proximity causes them to be affected by the magnetic fields of their neighboring dots and become unstable, according to the researchers—a group of chemists and engineers at UT Austin.

"The industry is now at about a terabit of information per square inch," said C. Grant Willson, professor of chemistry, biochemistry and engineering at UT Austin. "If we moved the dots much closer together with the current method, they would begin to flip spontaneously now and then, and the archival properties of hard disk drives would be lost."

Leon Dean, an undergraduate chemical engineering major at the University of Texas-Austin, was part of the team that developed the new process for increasing the capacity of hard disk drives.

Credit: Alexander Wang, University of Texas-Austin

But if the dots are isolated
from one another with no magnetic material between them they can be
pushed closer without destabilization. Block copolymers coated on a disk
surface are capable of self-assembling into highly regular patterns of
dots or lines at room temperature, given the right prod, the researchers
say. If the surface onto which they're coated already has some
guideposts etched into it, the dots or lines will form into precisely
the patterns needed for a hard disk drive, according to the researchers.